Abstract: A controller for an HVAC system having a plurality of zones and having a multiple stage fluid temperature conditioning device. The controller is configured to receive a plurality of thermostat signals and to transmit a signal to control one of a plurality of flow control devices in response to a call for conditioning in one of the plurality of zones. The controller also includes one or more timers that are connected to the thermostat terminals, where the one or more timers are configured to initiate a separate timing count upon each call for conditioning in any one of the plurality of zones. In addition, the controller includes one or more staging terminals for transmitting staging signals to control a multiple stage fluid temperature conditioning device, where the transmission of the staging signals determines whether the conditioning device will operate at a relatively higher output stage.

Abstract: A vehicle air conditioner includes an air-conditioning ECU. The air-conditioning ECU performs a cooling mode operation in which air is cooled by an interior heat exchanger in a cooling refrigeration cycle. The air-conditioning ECU performs a heating mode operation, in which air is heated by the interior heat exchanger in a hot gas heater cycle. The air-conditioning ECU performs an air blowing operation in which air is blown toward an inner surface of a windshield of the vehicle without operating the compressor before performing a refrigerant collecting operation.

Abstract: Adaptive intelligent circulation control methods and systems are used to help increase the comfort and/or reduce energy usage and equipment wear. In one illustrative embodiment, the circulation and/or ventilation time is adjusted based on one or more environmental conditions inside or outside the building structure. In another illustrative embodiment, the circulation and/or ventilation time may be adjusted based on the current time of day, current time of year, and/or the current schedule period. In another illustrative embodiment, the circulation and/or ventilation time is randomized over time. The start time, end time, and/or length of a circulation and/or ventilation cycle may be randomly set.

Abstract: In a refrigeration cycle apparatus having an expansion mechanism, a method to swiftly generate a pressure difference upstream and downstream of the expansion mechanism of, thereby enhancing the starting performance of the refrigeration cycle apparatus The apparatus has a compression mechanism, a utilizing-side heat exchange, an expansion mechanism for recovering power, and a heat source-side heat exchanger. The revolution number of the heat source fluid transfer means is made smaller than a target revolution number or the heat source fluid transfer means is stopped during a predetermined time after the compression mechanism is started. When the compression mechanism is started, the pressure difference can be generated upstream and downstream of the expansion mechanism for a short time, the operation of the expansion mechanism does not become unstable, vibration and noise can be prevented, and the refrigeration cycle apparatus can swiftly be started.

Abstract: A refrigeration unit and diagnostic method therefore are provided. The refrigeration unit includes: a housing with an insulated cavity for storing food and beverages; a vapor cycle system operative to cool the food and beverages in the insulated cavity; a plurality of sensors in communication with the vapor cycle system and outputting data relative to the vapor cycle system; and a controller that, according to the data from the plurality of sensors, determines an occurrence of an event. Wherein the controller logs the data from the plurality of sensors to a data structure according to a first data-logging mode, and logs the data to the data structure according to a second data-logging mode upon occurrence of the event. In one embodiment the refrigeration unit may be a refrigeration line replaceable unit (LRU) configured for an aircraft galley.

Abstract: A refrigerator which includes a refrigerating compartment and a freezing compartment, a first evaporator and a second evaporator corresponding to the refrigerating compartment and the freezing compartment, respectively, a compressor compressing refrigerant to be supplied to the first and second evaporators, a first fan and a second fan supplying cool air to the compartments, respectively, an external temperature sensor detecting an external temperature of the refrigerator, a multi-directional valve supplying the refrigerant to at least one of the evaporators, and a control unit operating the compressor and the multi-directional valve, and driving the first fan and the second fan until temperatures of the compartments reach a predetermined reference temperature.

Abstract: The control means (41 and 42) cause the air conditioner to start air temperature control when temperature To of the outdoor air is in a pre-set range at the time of starting the air conditioning system (1), after the lapse of a pre-set time since the humidity controller (10) started adjusting air humidity. The room temperature nears the humidity set value Rs during the time air temperature control is started in the air conditioner (20).

Abstract: A control system for controlling delivery of either heated or cooled water over a common water line to a plurality of heat exchangers. The control system includes a hydronic system controller which polls the heating or cooling demands of zone controllers controlling the respective delivery of water to the individual heat exchangers. The hydronic system controller is operative to implement a changeover between delivery of heated water to delivery cooled water or vice versa. The implemented changeover preferably includes checking the temperature of the water being returned to the source or sources for heating or cooling the water as well as defining a changeover time period which must occur in the event that the temperature of the water in the return line is not within a predefined range.

Abstract: A heat pump, and in particular a heat pump for heating a hot water supply is provided with an improved defrost mode. The defrost mode is actuated to remove frost from an outdoor evaporator that may accumulate during cold weather operation. An algorithm for operation of the defrost mode is developed experimentally by seeking to maximize the heat transfer provided by the refrigerant. A heating system condition is experimentally related to the heat transfer capacity. One then maximizes the average heat transfer capacity to determine the optimum initiation point for the defrost mode. Further, protections are included into the defrost mode. When the heat pump is utilized to heat hot water, methods are provided to prevent the water that remains in the heat exchanger from becoming unduly heated. In one method, the water pump may be periodically operated to move the water.

Abstract: The present invention realizes a reliable heat pump apparatus and heat pump apparatus having high recovering efficiency. The heat pump apparatus includes an expander 711 for expanding working fluid, a permanent magnet type synchronization power generator 710 which is disposed for recovering power by the expander 711 and which generates three phase AC power, and a first converter 708 which converts the AC power to DC power, and which rotates the power generator 710 at a predetermined target number of revolutions by switching of a switching element group 709. The generated electricity is consumed by connection of an AC power supply 701 to a DC power line which is rectified and smoothened by a rectifier circuit 702 and a smoothing capacitor 703, and by driving of an electric motor 706 which rotates a compressor 707 through a motor drive apparatus 704, and the power is efficiently recovered.

Abstract: A method for adjusting a natural refrigeration cycle rate of an air conditioner includes monitoring a time between at least two sequential refrigeration “off” events or at least two sequential refrigeration “on” events, and determining whether the time is below or above a predetermined time. If the time is below the predetermined time, the method further includes increasing a refrigeration “on” temperature threshold. If, however, the time is above the predetermined time, the method further includes decreasing the refrigeration “on” temperature threshold.

Abstract: A method of controlling a HVAC system for a hybrid vehicle having a refrigerant compressor driven by an engine is disclosed. The method may comprise: determining a requested air conditioning operating point for a passenger compartment; estimating a time to reach the requested operating point; based on the previous steps, estimating a maximum allowed compressor off time; determining if the allowed compressor off time is greater than a minimum engine off time; if the allowed compressor off time is greater than the engine off time, determining if the vehicle is entering an allowable engine off mode; if so, commencing engine shut-off mode; if engine shut-off is anticipated, prior to commencing the shut-off mode, adjusting the HVAC system to maximize cooling of the passenger compartment with minimum energy usage; and if the engine shut-off is commenced, monitoring the HVAC system to determine when engine restart is needed to maintain comfort.

Abstract: An HVAC system includes a variable speed electric motor driven fan for circulating air to an enclosed space through an indoor unit for providing heating or cooling effect to air circulated through the indoor unit. A controller with user or system installer actuatable switches includes a programmable microcontroller providing a pulse width modulated (PWM) signal to a motor control unit to select a predetermined air flowrate less than full air flowrate during system startup and shutdown. User input parameters include selected percentages of full air flowrate to satisfy requirements for reduced noise level, lower humidity and for improved sensible heating of air being circulated, the latter being effective particularly for heat pump applications. Selection of pre-run, short run and shutdown cycles may be provided.

Abstract: A refrigeration unit and a respective control and management assembly, comprising a refrigeration assembly and at least one power input for its electrical power supply. The refrigeration unit comprising at least one signal input and at least one control switch, which is arranged along a power line which corresponds to the power input. The control switch controlling the power line and the data that arrive from the respective signal input being suitable for driving the control switch for consequently determining the presence/absence of electrical power supply for said refrigeration assembly.

Abstract: A method for configuring a communicating environmental conditioning network having a plurality of environmental interactive units communicatingly coupled with a plurality of space interactive units, each respective space interactive unit presenting a conditioned output when engaged with a particular environmental interactive unit, includes: (a) turning on selected delivery elements associated with selected space interactive units; (b) establishing baseline data indicating conditioned outputs of the selected space interactive units; (c) engaging at least one respective space interactive unit with at least one respective environmental interactive unit; (d) waiting a predetermined time interval; (e) measuring a conditioned output associated with each the selected delivery element; and (f) selecting the respective selected space interactive unit associated with the largest change in the conditioned output as assigned to the respective environmental interactive unit.

Abstract: A refrigeration device is provided and includes a compressor with a compressor inlet and a compressor outlet, an evaporator with an evaporator inlet and an evaporator outlet, a valve, connection lines, and a control unit. The compressor and the evaporator are part of a coolant circuit and the valve is arranged in the coolant circuit between the compressor outlet and the evaporator inlet. The compressor and the valve are actuated by the control unit, wherein the control unit has a delay unit which causes the compressor to be switched on with a time delay only after the valve is opened.

Abstract: A system and method for detecting failure of a cooling system in an alternating current machine, such as a motor and/or a generator. For example, in one embodiment energy wasting is initiated and a failure is indicated if a temperature rises by more than a selected amount over a selected time period.

Abstract: A cooling system for a heat producing system includes a heat exchanger in fluid communication with the heat producing system. The heat exchanger is configured to receive a temperature control fluid therethrough. A first fan is operable in a first rotational direction to move air through the heat exchanger in a first direction. A second fan is disposed radially adjacent to the first fan, and is operable in a second rotational direction opposite the first rotational direction to move air through the heat exchanger in the first direction. A control system, including at least one controller, is provided for controlling operation of the fans.

Abstract: A compressor is operable to compress refrigerant at a variable operation frequency. According to a method of controlling the compressor, the compressor starts operating, and just after that, the compressor operates at a first frequency for a first period of time. Just after that, the compressor operates at a second frequency lower than the first frequency for a second period of time longer than the first period, and after that, the compressor operates at an ordinary operation. This method does not cause the compressor to generate an abnormal noise or obstruction to lubrication.

Abstract: This invention discloses a gasoline-saving vehicle A/C controller, comprising a timer with a control button and a junction. The control button of the timer is set to a pre-determined ON/OFF schedule; the junction is switched on and off by the timer in accordance with the ON/OFF schedule of the control button. The junction is connected in series to the thermo control system. When the junction is electrically activated, the vehicle A/C system of clutch relay, the compressor clutch and the compressor is correspondingly activated.

Abstract: A controller for an HVAC system having a plurality of zones and having a multiple stage fluid temperature conditioning device. The controller is configured to receive a plurality of thermostat signals and to transmit a signal to control one of a plurality of flow control devices in response to a call for conditioning in one of the plurality of zones. The controller also includes one or more timers that are connected to the thermostat terminals, where the one or more timers are configured to initiate a separate timing count upon each call for conditioning in any one of the plurality of zones. In addition, the controller includes one or more staging terminals for transmitting staging signals to control a multiple stage fluid temperature conditioning device, where the transmission of the staging signals determines whether the conditioning device will operate at a relatively higher output stage.

Abstract: An apparatus for controlling a stop operation of an air conditioner includes: a compressor for compressing a refrigerant; an indoor heat exchanger for heat-exchanging between the refrigerant and indoor air; an indoor fan for blowing the heat-exchanged indoor air to indoors; and a controller. The controller controls, in response to an operation stop signal in operation, an operation of the indoor fan based on whether or not an operation of the compressor has completely stopped.

Abstract: A method and apparatus for producing a chilled or partially frozen beverage is provided. The system includes a beverage hopper (32) a chilling unit (44), a rotatable mixing member (38), a sensing member (230) for detecting an occurrence of a rotation reversal condition, a controller for generating a rotation reversal signal in response to the sensing member, and a drive motor (36) coupled to the mixing member for rotating the mixing member in a first direction and a second, reverse direction in response to a rotation reverse signal.

Abstract: A repositionable attenuator for a terminal unit in a heating, ventilation, and air conditioning system is disclosed. The attenuator is positionable between at least a first and a second position. This enables the attenuator to be attached to and shipped with the terminal unit prior to installation of the terminal unit.

Abstract: The present invention relates to control of a fan during which the power of the fan is determined from the characteristic curves of the fan motor, the operating parameters of the cooling system and the reference variables which are predefined in the form of temperature levels. The various temperature levels which are to be set have different associated characteristic curves for actuating the fan motor. If the reference variable for the control changes, this also means a change in the characteristic curves for actuating the fan motor. In order to prevent the fan motor from whining, the operation of the fan motor is kept constant for a settable minimum waiting time when the reference variable for the control of the fan changes.

Abstract: A refrigerator includes a housing that encloses at least one interior space, a low temperature generator or refrigerating machine for cooling the interior space, and a control device for receiving a target signal and for controlling the temperature of the interior space to a target temperature represented by the target signal, by controlling the operation of the refrigerating machine. A control element supplies the target signal to the control device with a level that varies in accordance with a predetermined course.

Abstract: A vehicle air conditioner includes a non-contact temperature sensor for detecting a temperature in a predetermined area of a passenger compartment in non-contact, an air conditioning unit that controls an air conditioning state in the passenger compartment based on at least the temperature detected by the non-contact temperature sensor, and an air conditioning ECU for controlling the air conditioning unit. The ECU determines whether the temperature detected by the non-contact temperature sensor is abnormal, and informs a determination result to a user by using a light emitting diode. Thus, it is possible to notify the user whether the temperature detected by the non-contact temperature sensor is abnormal. The determination whether the detected temperature of the non-contact temperature sensor is abnormal can be performed by using at least one of the temperature detected by the non-contact temperature sensor and an environment condition.

Abstract: Parameters are set in accordance with a running condition of a vehicle and an environmental condition based on a wiper operation signal of the vehicle. The parameters are used to calculate a stable vehicle interior surface temperature Tna of a window glass. The stable vehicle interior surface temperature Tna and a vehicle interior surface temperature Tn1 calculated at previous sampling are used to calculate a vehicle interior surface temperature Tn in a transient state considering response delay time ? of temperature change. A control temperature, at which no dew is formed on the window glass, is determined in accordance with the obtained vehicle interior surface temperature Tn to perform air conditioning control.

Abstract: When it is assumed that a vehicle is stopped or parked after its engine was stopped and a predetermined period of time has passed, a cold wind side air mixing door, hot wind side air mixing door, cold wind door and rear cold wind side air mixing door are totally closed and a blower is operated for a predetermined period of time. Accordingly, while a cooler is being dried, drying air containing much offensive smell components, which has passed through the cooler, is discharged outside the vehicle. Therefore, it is unnecessary to provide an exclusively used air passage and an opening and closing door for opening and closing the air passage used for composing an air blowing passage to dry the cooler. By utilizing the existing equipment, air used for drying, which has passed through the cooler, containing much offensive smell components can be discharged outside the vehicle.

Abstract: Adaptive intelligent circulation control methods and systems are used to help increase the comfort and/or reduce energy usage and equipment wear. In one illustrative embodiment, the circulation and/or ventilation time is adjusted based on one or more environmental conditions inside or outside the building structure. In another illustrative embodiment, the circulation and/or ventilation time may be adjusted based on the current time of day, current time of year, and/or the current schedule period. In another illustrative embodiment, the circulation and/or ventilation time is randomized over time. The start time, end time, and/or length of a circulation and/or ventilation cycle may be randomly set.

Abstract: A no-frost refrigerator includes at least one storage compartment, an evaporator, which can be switched on and off and is disposed in a chamber that is separate from the storage compartment, and a fan for driving an exchange of air between the storage compartment and the chamber. Of the evaporator and fan, at least one can be operated while the other is switched off.

Abstract: An ice-making machine and method of maintaining and cleaning an ice-making machine are provided. The ice-making machine has predictive maintenance and cleaning. Operational conditions of the ice-making machine, such as, for example, water quality, are used to establish service intervals and/or types of service, and the service intervals and/or types of service are indicated to the user with a lead-time to allow for timely obtaining the service.

Abstract: Disclosed is a method for controlling an air conditioner having a multi-compressor capable of improving an ability that corresponds to a room cooling load or a room heating load and capable of reducing an energy loss of the air conditioner. To this end, a compressing capacity of compressors by a temperature difference between a previous room temperature and a desired temperature predetermined by a user is pre-stored. Then, the pre-stored compressing capacity is varied on the basis of a temperature difference between a present room temperature and the desired temperature.

Abstract: A method and apparatus for controlling the operation of an air conditioning system and a plurality of auxiliary devices, with both the air conditioning system and the auxiliary devices being adapted to operate in a setback condition. The auxiliary devices are operated in a setback condition in response to the operation of the setback operation of the air conditioning system such that, generally, the auxiliary devices are operated in a setback condition when the air conditioning system is operating in a non-setback condition and vice versa so as to thereby achieve load balancing. In addition, the auxiliary devices can, at the same time, be operated in the setback mode on the basis of duty cycle.

Abstract: A programmable thermostat with a heat-cool switch, a temperature value input, and a fan switch with on, auto, and recirculating positions, and a microprocessor that superimposes a fan recirculating mode or cycle on the heat-cool or off modes or cycles by determining when the heat-cool or off cycles have been off for a user selectable time period; 2 hours, for example, and if so initiating a fan cycle for a predetermined time; 12 minutes for example, to provide a more uniform room temperature by mixing hotter and cooler air and cleaner air by running more space air through the heating and cooling system filter assembly.

Abstract: A refrigeration system is employed to cool a refrigerated compartment in a kitchen or restaurant. An electronic refrigeration controller controls various aspects of the refrigerated compartment, including temperature. When a push button is pressed, a “sleep-mode” is activated to safely shut the refrigeration system down and turn the evaporator fan off. An employee can then stock or remove inventory from the refrigerated compartment without cool air blowing on the employee. After a predetermined amount of time, the sleep-mode ends and cool air blows into the refrigerated compartment.

Abstract: A freezing prevention system for a refrigeration device includes a freezing-prevention temperature sensor for detecting a refrigerant temperature in a refrigerant evaporator, and a control unit for controlling operation of a refrigerant compressor based on the detected refrigerant temperature. The control unit includes a calculating means for calculating an integral value of the detected refrigerant temperature integrating with respect to a passed time after the detected refrigerant temperature becomes equal to or lower than 0° C. When the integral value becomes equal to or larger than a predetermined value, the control unit stops the operation of the refrigerant compressor. Accordingly, the freezing prevention system can accurately perform a freezing prevention control while its production cost can be reduced.

Abstract: A compressor assembly having a first compression mechanism operatively coupled to a first motor and a second compression mechanism operatively coupled to a second motor. The first compression mechanism compresses the vapor from a low pressure to an intermediate pressure and the second compression mechanism compresses the vapor from the intermediate pressure to a discharge pressure. An electrical circuit supplies electrical current to the first and second motors during operation of the compressor assembly. The electrical circuit includes means for, during start-up of the compressor assembly, initiating the supply of electrical current to the first motor at a first time and initiating the supply of electrical current to the second motor at a second time wherein the first time precedes the second time by a time lapse.

Abstract: Methods and apparatus for more effectively managing humidity of an inside space using an air conditioner are provided. In one illustrative embodiment, the system determines whether the humidity level in an inside space is above a predetermined humidity threshold, and if so, changes a control parameter such as a minimum “on” time for the air conditioner. If the humidity level in the inside space is not above the predetermined humidity threshold, the control parameter is not changed, or changed less than when the humidity level is above the predetermined humidity threshold. Rather than changing (i.e. increasing) the minimum “on” time, it is contemplated that any control parameter that increases the “on” time of the air conditioner may be used including, for example, changing (i.e. decreasing) the maximum cycle rate allowed for the air conditioner.

Abstract: The object of this invention is to provide an air conditioner with a variable capacity compressor (2) parallely connected to a fixed capacity compressor (4), and a method of controlling the operation of such an air conditioner. When it is required to start the fixed capacity compressor (4) in addition to an operation of the variable capacity compressor (2) due to an increase in the sum of the required cooling capacities of indoor units (9), an outdoor control unit (13) starts the fixed capacity compressor (4) during an unloading mode operation of the variable capacity compressor (2) where the pressure difference between the outlet side and inlet side of the variable capacity compressor is minimized. The fixed capacity compressor (4) is thus smoothly started without causing an induction of excessive starting current, and improves the operational reliability of the air conditioner.

Abstract: Disclosed is a method for controlling noise reduction of an air conditioner comprising the steps of: (a) stopping a compressor, when the air conditioner is stopped under the condition that the compressor and an outdoor fan are operated; and (b) stopping the outdoor fan after a designated time after a point in time when the compressor is stopped in the step (a) elapses, thus reducing the size and duration of noise generated by the flow of the refrigerant due to a difference of inner pressures in the air conditioner and allowing the noise at a designated frequency band generated by the flow of the refrigerant, which causes unpleasantness to users, to be concealed by noise generated by the operation of the outdoor fan. Accordingly, the method of the present invention increases reliability of air conditioner products.

Abstract: A refrigerated appliance that dispenses items includes a power source and a cooling system. Power control circuitry is electrically coupled between a power source (e.g., power cord coupled to a wall outlet) and components (for example, a compressor and one or more circulating fans of the cooling system) of the appliance. A controller, which is operably coupled to the power control circuitry, is adapted to manage the supply of electrical power to such components by intelligently transitioning between a normal-operation mode and at least one power-conserving mode. To achieve efficient power conservation, the controller automatically transitions between the at least one power-conserving mode and the normal-operation mode based upon at least one temperature signal, at least one dispensing event signal, and possibly other data signals supplied to the controller.

Abstract: An automatic stop/start controller for an engine, having an air conditioner which employs a coolant or driving force of the engine to control the air in a driver's compartment. The engine can be stopped and started without operation of an ignition key. After a predetermined automatic stop condition is satisfied and the engine is automatically stopped, a control unit maintains the engine in a stopped state as long as the duration of an automatic stop of the engine is shorter than an automatic stop maximum time set based on air temperature at an inlet of the air conditioner.

Abstract: A compressor is controlled by generating and storing a compressor operation log. In addition, a compressor operation is selected from the compressor operation log in response to a sensor failure. Furthermore, the compressor is modulated according to the selected compressor operation in response to the sensor failure.

Abstract: Disclosed are an air conditioning system with two compressors and a method for operating the same, so as to variably change a compression capacity of a refrigerant according to the variation of cooling load. Herein, when a full operation order is inputted to the two compressors in order to satisfy increased cooling load, the first compressor is first operated, and then the second compressor having a compression capacity of a refrigerant smaller than that of the first compressor is additionally operated, so that a current peak value for operating the compressors does not exceed an allowable current range of a circuit breaker installed in a home or building, thereby safely controlling the air conditioning system and simultaneously allowing the current to be provided to other electric appliances, thus improving users' convenience.

Abstract: A system and method of providing floating actuator control is provided. This system and method receives input command signals from an actuator controller, and effectively integrates these signals until the controller has requested a large enough movement of the actuator that the actuator can actually effectuate. At this point, the system and method drive the actuator to the commanded position. As a result, excessive mechanical wear in the actuator caused by small command signal perturbations and dither is reduced or eliminated.

Abstract: An apparatus and method for drying condensate from the heat exchanger of a vehicle's air conditioning system after operation in order to thwart odor buildup is provided. The apparatus and method operate regardless of whether the system's blower control circuit is positively or negatively switched. The apparatus includes relays that bypass the normal operating electrical routing to the air conditioning system's blower motor to operate the blower directly. The method comprises determining that the engine of the vehicle has been switched off and that the air conditioning system of the vehicle was in operation prior to the engine being switched off. If the conditions are met, the air conditioning system's blower is operated on a predetermined time schedule to circulate air in the air conditioning system to dry condensate therefrom. In this way, growth of odor-causing fungus and bacteria is inhibited.

Abstract: A first solenoid-operated, discharge-line control valve (26) is moved between open and closed positions to control fluid flow in the discharge fluid line (18) between the compressor (12) and the condenser (14). A second solenoid-operated, liquid-line control valve (28) is moved between open and closed positions to control fluid flow in the liquid fluid line (20) between the condenser (14) and the evaporator (16). A controller (36) closes one of the flow control valves (26, 28) a period of time before closing the other flow control valve (26, 28) and shuts down the compressor (12) sequentially with the flow control valves (26, 28).

Abstract: An air conditioning system and a method for operating the air conditioning system, in which a plurality of compressors are simultaneously or selectively operated, based on the difference between a room temperature and a desired temperature generated during a waiting time for re-operation of the compressors. The room temperature varying during the waiting time for the re-operation of the compressors maintained at a stopped state is sensed to determine whether or not an increase in cooling load occurs. Based on the amount of the cooling load, it is determined whether the compressors have to operate simultaneously or selectively. That is, the refrigerant compression capacity of the air conditioning system is determined by reflecting the cooling load caused by a variation in room temperature occurring during the waiting time for re-operation taken until any compressor maintained in a stopped state is re-operated.

Abstract: The present invention relates to systems and methods for controlling head pressure in a vapor compression system, e.g. in a precision air conditioning system. One embodiment of the invention provides a method for regulating working fluid flow in a vapor compression system including a compressor. The method includes: providing a controller; receiving signals at the controller representative of a monitored discharge pressure in a discharge line of the compressor; and using the controller to provide a control signal to an actuator that controls a flow control valve that, in turn, controls working fluid flow into the system, the control signal being responsive at least in part to a difference between a set point pressure and the monitored discharge pressure.